The present invention relates to an apparatus for turning substantially spherically-symmetrical articles, such as eggs.
In particular, the invention relates to an apparatus for turning eggs, with the eggs located on rollers which are mounted on axes of a roller conveyor, and with a detection device for scanning the direction of orientation of each egg during transport on the roller conveyor, and with turning elements mounted on an endless chain, which turning elements during transport on the roller conveyor pick up the eggs from the roller conveyor, turn the eggs with the point in a pre-set direction, and subsequently deposit the eggs onto a next transporting apparatus.
It is generally known that a uniform orientation of the eggs is required to ensure both the storage life of the eggs and the safe packaging of the eggs. To effect such a uniform orientation, in the past a variety of apparatuses have been devised and implemented.
Such an apparatus is known, for instance, from U.S. Pat. No. 5,749,453, which describes how eggs are supplied to a so-called turning mill. Located on rollers of a roller conveyor, the eggs, directly upstream of the turning mill, reach a saddle-shaped stop element which in all cases pushes the eggs with the big end in the direction of movement of the roller conveyor. Immediately after that, the eggs are picked up by grippers of the turning mill, turned in the desired direction during rotation of the mill, and thereafter laid onto a next roller conveyor for further handling.
The new generation of egg sorting machines is subject to far-reaching requirements regarding hygiene. This makes the use of a smaller model of rollers necessary, thereby enabling the interposition of devices for removing, for instance, leaking eggs.
It is precisely these smaller rollers that make the use of the above-mentioned apparatus unreliable because the eggs, upon being stopped by the stop element, will not always turn in the right direction.
To remedy the above drawback, the apparatus according to the invention is characterized in that the turning elements turn only those eggs which, as indicated by a turning signal delivered by the detection device to the turning apparatus, do not point in the pre-set direction.
In a particular exemplary embodiment, each turning element consists of a rotary element mounted on one of the ends of a rotary shaft, and a gripper suspension frame connected with the other end of the rotary shaft, the shaft being received in a housing having therein a coupling element for coupling or uncoupling the rotary element and the frame, and an actuator for operating the coupling element, the apparatus further comprising a rotation driving element.
What is thus achieved is not only that all eggs have their point pointing in the same direction, but also, in an advantageous manner, a higher processing rate is accomplished, since the mechanical handling as mentioned above can only deal with rates of up to 10,000 eggs per hour.
In a further exemplary embodiment of the apparatus according to the invention, the rotary element consists of a star wheel with four star wheel blades of which the opposite blades are mounted as pairs above each other on the rotary shaft, and upon advancement of the chain the pairs of the star wheel are guided and rotated along curves of a curve path correspondingly arranged above each other.
In this way, a highly uniform and ensured rotation is obtained which prevents accidents and damage to delicate products as eggs are.
The present invention also relates to an apparatus and method for turning substantially spherically-symmetrical articles, such as eggs.
More particularly, the invention relates to an apparatus and method for turning eggs, with the eggs located on rotary rollers mounted on axes of a roller conveyor, and with a detection device for scanning the direction of orientation of each egg during transport on the roller conveyor, and with turning elements mounted on an endless chain, which turning elements during transport on the roller conveyor turn the eggs with the point to the predetermined direction, and subsequently deposit the eggs on a next transporting apparatus.
It is customary to have eggs rotate as soon as they are deposited from supply units such as pallets, boxes or containers, onto rollers of supply rows. Due to the rotary movement which the eggs then follow, the long axes or main axes of the eggs will come to lie substantially parallel to the axes of the rollers of the roller conveyor, thereby preventing skewed or upward orientation of the eggs, and hence an increased risk of damage or breakage. Incidentally, both the shape of the eggs and the shape of the rollers, generally designated as hourglass-shaped, have as a consequence that the points of the eggs will lie in one of the two directions of the axis. Moreover, due to the spinning of the eggs, their centers will be displaced with respect to the centers of the rollers on which they lie.
It is generally known that a uniform orientation of the eggs is required to ensure both the storage life of the eggs and the safe packaging of the eggs. To effect such a uniform orientation, in the past a variety of apparatuses and methods have been devised and implemented.
Such an apparatus is known, for instance, from U.S. Pat. No. 5,749,453, which describes how eggs are supplied to a so-called turning mill. Located on rollers of a roller conveyor, the eggs, directly upstream of the turning mill, reach a saddle-shaped stop element which pushes the eggs with the big end in the direction of movement of the roller conveyor. Immediately after that, the eggs are picked up by grippers of the turning mill, turned in the desired direction during rotation of the mill, and thereafter laid onto a next roller conveyor for further handling.
The new generation of egg sorting machines is subject to far-reaching requirements regarding hygiene. This makes the use of a smaller model of rollers necessary, because this enables the interposition of devices for removing, for instance, leaking eggs.
It is precisely these smaller rollers that make the use of the above-mentioned apparatus unreliable, because the eggs, upon being stopped by the stop element, will not always turn in the right direction.
To remedy the above drawback, the apparatus according to the invention is characterized in that the detection device consists of a device for effecting images of the eggs which pass on the roller conveyor and for electronically processing the images, while an orientation signal is formed which represents for each egg the direction in which the point of the egg points, each signal is compared with a predetermined signal feature associated with a set orientation, and a turning signal is delivered to the turning apparatus for turning the eggs in the desired direction.
What is thus achieved is not only that all eggs have their point pointing in the same direction, but also, in an advantageous manner, a higher processing rate is accomplished, since the mechanical handling as mentioned above can only deal with rates of up to 10,000 eggs per hour.
In a further exemplary embodiment of the apparatus according to the invention, the detection device further comprises for each egg when passing, a light source for illuminating the egg passing on the rollers, and a camera surface, provided parallel to the axes of the roller conveyor, with a surface extending over at least the main axis of an egg, while at least one substantially umbral image of the passing egg is formed.
In a further advantageous exemplary embodiment of the invention, the camera surface is divided into two halves at the center of each passing roller. In this way, a single recording can suffice and use can be made of the off-centre or also the asymmetrical location of, in particular, the centers of each egg on the rollers.
Further, the present invention provides a method characterized by
imaging the eggs which pass on the roller conveyor,
electronically processing the images obtained upon imaging, whereby an orientation signal is formed which represents for each egg the direction in which the point of the egg points,
comparing each orientation signal with a predetermined signal feature associated with a set orientation, and
delivering a turning signal for turning the eggs in the desired direction.
More particularly, the invention comprises an exemplary embodiment comprising
illuminating each egg passing on the rollers,
imaging the egg on a camera surface parallel to the axes of the roller conveyor, with a surface extending over at least the main axis of an egg, while at least one substantially umbral image of the passing egg. is formed.
In a further exemplary embodiment, the linear imaging of the egg takes place parallel to the axes of the roller conveyor, whereby a linear image of at least a part of the egg parallel to the main axis thereof is formed.
In a further advantageous exemplary embodiment of the present invention, the egg is imaged on a camera surface which is divided into two halves at the center of each passing roller.
Thus, in a highly suitable and simple manner, reliable and easily processable information is obtained, which uniformly represents the orientation of the egg.
In a further advantageous exemplary embodiment of the invention, the method is characterized by:
comparing lengths or parts of lengths of each linear image with which an orientation signal is obtained,
comparing this orientation signal with the signal feature, and
subsequently generating the turning signal.